JNCC Offshore Survey to Anton Dohrn Seamount and East
Rockall Bank

Offshore Survey Diary - July 2009

On 1st
July four members of JNCC's Marine Protected Sites team headed to
sea on a three week survey off north-west Scotland. Neil Golding,
our Offshore Survey Manager, is sending back a diary to keep us
up-to-date with the new discoveries as they happen. The team will
be using state of the art technology to explore and map the seabed
in what is one of the least studied areas of our seas. They will be
visiting Anton Dohrn Seamount (an underwater mountain rising from
the seabed at a depth of 2,100 m) and East Rockall Bank and are
hoping to discover deep sea biogenic and rocky reef communities
that might be suitable for selection asoffshore Special Areas of Conservation
(SACs).

The team havepreviously visitedmany
other areas of sea around the UK undertaking surveys to find out
what habitats and species are present. Several of these places,
such as the Dogger Bank, have since been recommended to UK
Government for selection as SACs.

We were woken this morning by the sound of the anchor coming up
and the engines starting, so we knew we were leaving our sheltered
spot in St. Kilda. Neil had stayed up until 2am this morning to
await the most up-to-date weather forecast. Sadly, the low pressure
area that has been plaguing us for days showed no signs of moving
away, so we had to accept defeat - a return to Anton Dohrn was not
possible.

Ironically, during the first part of the journey home we had
some warm sunshine, though the winds were still brisk and the waves
still relatively high. The process of packing up the equipment and
storing all the data appropriately began - a sure sign that the
survey was now officially winding to a close. We set about
organising our travel home from our arrival port of Scrabster.
There was time for a final photograph with the crew before finally
arriving at 10pm - the survey was over! All that remained was the
long journey south home to Peterborough and the knowledge that the
easy part was over – the working up and reporting of the data would
continue for many months to come!

Day 27 - Monday 27th July

Alas…a new dawn brought more wind! The vessel moved around to
Village Bay on the south side of the island to get some cover from
the wind. Although the wind had changed direction round to the
north west, the weather remained too foul to leave the protection
of St Kilda. Some of the crew ventured ashore to download data from
a tide gauge positioned on the jetty. Whilst there, they were
informed by some of the islanders that the strong winds (up to 60
knots) meant that they could not drive their vehicles up to the
weather station on the hill. Even on the MV Franklin sheltered
within the bay, the weather station up on the bridge was recording
wind speeds almost that strong! Unfortunately, we were approaching
the time when a decision would need to be taken as to whether to
continue the survey or head home. There was a possibility that we
could take advantage of a lull in the weather and head back to
Anton Dohrn. However, it was unclear whether the weather window
would be long enough to make this a viable option. The alternative
was to accept defeat and to run for port before the next band of
poor weather arrived, forecast for around Tuesday lunchtime. We
went to bed awaiting the arrival of a fresh weather forecast which
would make the decision for us.

Day 26 - Sunday 26th July

The team woke up to an unusual sight through their cabin
portholes. Instead of a great expanse of ocean, we were greeted by
the spectacular cliffs of St. Kilda draped in cloud. We had
travelled from Anton Dohrn to St. Kilda overnight; with an average
wind speed at the end of our transit of 55 knots (the bridge
informed us that this was almost a "Violent Storm" on the Beaufort
Scale!). Though we all had a good nights sleep, evidence of our
well-developed sealegs, we were still relieved to find shelter from
the wind in Glen Bay, on St Kilda's main island (Hirta).

Later in the afternoon, we crept out of the shelter of the bay
to see if conditions had improved. At the same time, we were
treated to incredible views of the dizzyingly sheer cliff faces and
their resident seabirds. Throughout the journey, gannets, skuas,
kittiwakes and gulls soared and dipped in the wind, flying in and
out of their colonies. We also spotted some Soay sheep teetering on
the edge of the steep green hillsides.

Despite this wonderful spectacle, it was disappointing that we
were unable to be out at sea collecting more data. We will continue
to monitor the weather situation overnight and tomorrow morning to
assess whether there will be any opportunity to return to Anton
Dohrn to complete our camera work.

Day 25 - Saturday 25th July

Today was a race against the storm - we had to be on our way to
shelter by the evening. We worked furiously throughout the night
and day to try to get through as many camera tows as possible
before the weather closed in. Our feelings were a combination of
delight at what we found and frustration that the weather would
prevent us from doing more. During the very early morning, the
night shift team conducted a tow down a parasitic cone off the
north western flank of Anton Dohrn seamount. We discovered a large
and pristine 'garden' of gorgonians with a truly incredible
diversity of species and colour. These remarkable discoveries
continued into the day shift, when two further tows, one along a
ridge and one across a series of mounds revealed dense Lophelia
pertusa reefs. All the habitats we filmed were in excellent
condition, and showed little or no evidence of human damage - an
increasing rarity in today's world.

We finally had the call that we were dreading. The master made
the decision to head for cover as the winds were picking up. We
turned tail and steamed towards the nearest shelter (a mere nine
hours away!) - the small isolated archipelago of St Kilda. Although
it was disappointing to cut our work short, we were comforted by
the fantastic images we had managed to collect and were looking
forward to seeing the iconic World Heritage Site of St Kilda.

Day 24 - Friday 24th July

Today was our last day of survey on East Rockall Bank. We
completed four video tows in total today, covering a variety of
different features, including a deep canyon. From the acoustic data
we observed escarpments on the edge of Rockall Bank. With the
camera equipment we discovered that these escarpments were
primarily steep rocky cliffs, with solitary corals and sponges.
From our images, we also observed marks on the seabed made by
fishing gear, along with several observations of discarded fishing
gear.

Before departing for Anton Dohrn we completed a plankton tow for
the Sir Alister Hardy Foundation for Ocean
Science. During the transit in the late evening the JNCC team
took advantage of the free kitchen to prepare some tasty treats for
the weekend - including apple crumble and chocolate crispy
cake.

As midnight approached the night shift team prepared themselves
for our first camera tow on the north western side of Anton
Dohrn.

Day 23 - Thursday 23rd July

Camera work continued throughout the night and into the early
morning in good weather. From the acoustic data, we had spotted
some mounds on the seabed, which we thought warranted further
investigation with the camera equipment. A camera tow over the area
in the early morning revealed a dense cold-water coral reef on the
top of the mound. Other video footage showed evidence of fishing
activity - we could see the marks made by trawl gear on the
seafloor.

We were accompanied for most of the day by a large flock of
fulmars and storm petrels sitting on the water around the boat.
They seemed to be under the mistaken impression that we were a
fishing boat and that some free supper might be coming their way at
any moment - sadly this was a waste of their time!

The weather forecast is looking good for the next 48 hours or
so, but then is due to deteriorate quite dramatically on Sunday,
with an average wave height of 7m predicted. Therefore we have had
to plan our work around this by prioritising the most important
areas and features for data collection.

Days 21 and 22 - Tuesday 21st July and
Wednesday 22nd July

On Tuesday we continued our transit out to Rockall and were met
by the 40kt winds on the way. Thankfully, the situation improved
and we were out on deck enjoying the warm sunshine by the early
afternoon. We spent much of the rest of the day reviewing the
multibeam and sidescan data and selecting the camera tow locations
for Rockall

We arrived on station very early on Tuesday morning and the
night shift consisting of Neil and Emma were ready to go! With the
bottomless supply of tea and coffee helping to keep us awake, we
got our first glimpse of the seafloor at the northern end of East
Rockall Bank. At 6am the day shift arrived to relieve the bleary
eyed night crew and a further three tows were completed over the
course of the day. We were all very excited to find large areas of
cold-water coral reef, which was home to lots of strange and
beautiful species. We got some great video footage and still images
of these areas.

However, all the action has not just been happening on the
seafloor. Despite the rough seas, whales were spotted by the crew
several times on Monday and Tuesday, but sadly we've been too busy
looking at the seafloor to think what might be happening on the
surface! Some of the crew managed to see a basking shark very near
the boat early on Monday morning, but our excuse this time is that
we were all in bed following a rough transit!

Day 20 - Monday 20th July 2009

Today was a day of change. We arrived into Stornoway in the
early morning to find the camera equipment awaiting our arrival.
Following a stock up of provisions for the ship, we waved goodbye
to Therese, Dave and some of the crew that had accompanied us for
the previous three weeks. Ken Hitchen from British Geological
Survey joined us to replace Dave as Scientist in Charge. After a
quick walk, followed by lunch in a local café, we arrived back on
board to meet the new crew. We had a short meeting where we
introduced each other and outlined the survey aims for the next 10
days.

We steamed out to sea in the early evening, testing the camera
equipment just outside Stornoway harbour. We then continued south
through the Minch towards Barra, nervously awaiting the 40 knot
winds that have been promised once we reach the Atlantic.

Day 19 - Sunday 19th July 2009

There were a few tired heads on Sunday morning after spending
the night hanging onto our bunks. Last night the sea was pretty
rough – those down in the lower cabins were kept awake by the
banshee like screaming of the vessel stabilising equipment
struggling to keep the boat on an even keel (and failing)! During
the day when we went over particularly large waves, the sound of
crashing plates could be heard from the kitchen. This was the type
of weather during which we didn’t envy the cook as he prepared
meals for everyone.

Therese spent several hours reviewing video data to see if some
of the unusual deepwater fish species could be identified. We also
had the chance to select possible camera transects for East Rockall
Bank. We were excited by the sheer number of interesting features
shown by the acoustic data.

Despite the weather we made good progress steaming to Stornoway,
heading round the southern end of the Outer Hebrides. As we steamed
into the Minch, we collected multibeam over Mingulay cold water
coral reef complex, first discovered by the Victorians. We expect
to arrive in port around 6am on Monday morning.

Day 18 - Saturday 18th July 2009

Today was the last day of multibeaming. Progress was good, and a
draft chart of south-east Anton Dohrn was produced. The crew have
been flat out trying to process all the acoustic data…. they are
certainly getting through the coffee. We now have coverage all
along the steep cliff on the east side of Rockall, with survey
lines branching out from this into deeper water, where we have
identified features such as canyons, escarpments and pinnacles. We
also have a block of acoustic data on the top of Rockall Bank where
we are investigating an area known as the iceberg ploughmark zone.
Many thousands of years ago, the bases of icebergs scraped along
the surface of the bank, creating a complex seabed topography.

After lunch, a few of us were watching a large flock of
fulmars…..but these were quickly abandoned when Therese spotted
three Ocean sunfish (Mola mola) right next to the
boat. Later in the afternoon, Neil joined some of the crew in
the kitchen to bake a dessert for Sunday dinner. Cimmy the chef
kept a watchful eye on proceedings.

We started the steam back to Stornoway in the evening with poor
weather predicted for the rest of the night. We were all warned to
secure fragile items such as laptops and cameras before going to
bed.

Day 17 - Friday 17th July 2009

We made good progress steaming south down the eastern flank of
Rockall Bank, collecting multibeam
bathymetry and sidescan
sonar data as we went. Over 200km of data were acquired,
showing some very interesting seabed features that will warrant
further investigation when we return with the underwater camera
equipment. In particular, the multibeam backscatter and sidescan
sonar line that we completed on the top of Rockall Bank showed
marks up to a metre deep across the seabed; some were straight
while others meandered. Work also started on producing the survey
charts that will showcase the data collected during the survey.

On the route down we saw a fishing vessel in the distance off to
our starboard side. We also saw a sailing yacht, which looked very
small and exposed in the vast expanse of ocean. Hopefully they will
find some shelter before the bad weather that is forecast, reaches
us at the weekend.

We read in the
news that the ferry due to bring the replacement camera
equipment across from mainland Scotland to Lewis had broken down,
creating a large backlog of passengers and cargo in Ullapool. A
replacement (albeit smaller) ferry had been organised to resume
normal service. Hopefully this won’t significantly delay the
arrival of the camera equipment, but it serves as a reminder that
while you can plan a survey to the ‘nth degree’, you
still need to be prepared for the unexpected!

Day 16 - Thursday 16th July 2009

Acoustic seabed mapping continued along the underwater cliff on
the east side of Rockall Bank. We gathered data along this cliff
all the way up to the northern end of Rockall Bank then steamed
back on a parallel course. In addition to the acoustic survey, the
analysis of the Anton Dohrn underwater camera tows have almost been
completed.

The weather conditions have been very good and have allowed us
to gather lots of good quality data. However, we have been watching
the weather forecast with trepidation, an area of low pressure that
could create gale force winds have been forecast for the weekend
and into next week. This may coincide with when we are planning to
start the camera work. With a bit of luck most of the bad weather
will happen whilst we are in Stornoway for a crew change on
Monday.

Thursday brought us a traditional Swedish lunch of yellow pea
soup followed by pancakes, jam and cream for dessert.
Apparently, this is served everywhere in Sweden on a Thursday.
Beth’s eyes were too big for her tummy, and she had to admit defeat
half way through her stack of pancakes…

A pod of pilot whales were spotted in the morning very close to
the boat. Although we missed them first time around, they made a
second appearance a few hours later. After a shout from the bridge
and a mad dash for the cameras, we managed to get a few pictures,
phew!

Day 15 - Wednesday
15th July 2009

In the early hours of the morning, we completed multibeam work
at Anton Dohrn and began steaming towards East Rockall. On the way
to Rockall, the sea was pretty rough, which caused some to almost
fall out of their bunks! We had now reached our furthest
point away from land and it was exciting to begin work in a new
study area. Multibeam data collection began just after
breakfast, continuing until the late afternoon and the sidescan
sonar was also deployed later in the day. This sidescan sonar
equipment was different to the deep-tow system (seen in Day 3 photo) – it has an autopilot
mode which allows it to maintain a fixed height above the seabed.
Analysis of the mutlibeam and sidescan data suggested that there
might be areas of hard substrate (possibly with coral) on a shallow
area of East Rockall. From previous work we have a good idea
of where fishing activity takes place and the data we have
collected so far allows us to clearly see trawl marks on
the seabed. These appear as two parallel straight lines which are
distinct from iceberg ploughmarks, which are also easily
identifiable in acoustic images but appear in more irregular
patterns. We hope to investigate this further with the camera
equipment later in the survey. The team are working their way
through the video data already collected, and are continuing to
find interesting fauna.

The weather has been very generous to us over the past few days,
with plenty of sunshine and light winds. The team were entertained
by some low-flying acrobatic fulmars, who spent the afternoon
racing alongside the boat. The bridge reported spotting pilot
whales, but they had gone by the time we had got on deck.

Day 14 - Tuesday 14th July 2009

We arrived at Anton Dohrn seamount early on Tuesday morning,
when multibeam data collection began. As the day progressed and the
data built up, the complex geomorphology of the north-western flank
of the seamount was revealed.

Meanwhile, analysis of video footage collected earlier in the
survey continued. The videos and images showed a diversity of
habitat types, as well some unusual species including previously
unreported anemones and sponges. In the evening, the team got
together to plan the next few days of multibeam data collection
over East Rockall, where we expect to begin working tomorrow
morning.

Day 13 - Monday 13th July 2009

Hoorah! We left Stornoway this morning and set sail for Anton
Dohrn seamount once again. Our plan was to reach the seamount by
the time the reported 6 metre waves had subsided. Flowers were hung
over the bow of the boat to attract good spirits; a traditional
practice of Thai fishermen. On the way out, we glimpsed the Flannan
Isles and St Kilda in the distant haze. We were also joined by a
pod of common dolphins and this time we got out on deck in time to
see them! This definitely lifted our spirits which had become quite
deflated with the extended periods of equipment down time that we
had experienced over the last week. We should be on station in the
very early hours of tomorrow morning, ready to start the acoustic
survey of north-west Anton Dohrn.

Day 10 - Day 12 - Friday 10th July - Sunday
12th July 2009

We discovered that getting spares to a remote Scottish island on
a summer weekend is a logistical nightmare! However, despite
all the ferries being fully booked the replacement parts for the
camera system eventually arrived but the communications problems we
had experienced with the camera kit persisted. Whilst repairs
were ongoing, the crew and scientists took the opportunity to
stretch their legs and see some of the local area. Perhaps
unusually for the west coast of Scotland, the sun shone all day
long on Saturday, and we were able to appreciate the standing
stones of Callanish in their full glory. By Sunday evening,
crucial repairs had been completed and we prepared ourselves for an
early morning departure on Monday.

Day 9 - Thursday 9th July 2009

The engineers were up most of the night working on the winches
and we left Stornoway harbour in the late morning to test the
repairs. During the testing of the main winch, a pod of
dolphins was spotted playing on the bow wave. Hearing this,
we all rushed on deck but unfortunately they had already moved
on. Once the testing of the winches was complete, the
hydraulics engineer was dropped back on shore using the small
safety boat. Meanwhile we started testing the camera system and it
became clear that the gremlins from last week were meddling again;
a communication problem had developed between the underwater camera
and the ship. There was nothing else for it - for the second
time that week, we found ourselves steaming back into
Stornoway.

Day 8 - Wednesday 8th July 2009

Today, a specialist hydraulics engineer arrived and repairs
continued on the main winch (used to deploy the deep-tow sidescan
sonar) and camera winch. During this period of downtime, we
took the opportunity to catch up with work that we would have been
doing back at the office – it's then that you appreciate having a
vessel with wireless satellite broadband! We also made
a start on preliminary analysis of some of the underwater video
footage. As dusk fell, work continued on the winches, and
into the night. If all goes according to plan, we should be
leaving in the morning to test the equipment, before transiting
back to the survey area around Anton Dohrn seamount.

Day 7 - Tuesday 7th July 2009

The journey from Anton Dohrn towards the Outer Hebrides
continued through the early hours of this morning through lively
seas. At midnight, Therese and Emma spotted the lighthouse on
Flannan Island, about 28 nautical miles away from us. We rounded
the Butt of Lewis at approximately 5am and we were alongside in
Stornoway by 10am.

Despite some cloud, it was a lovely mild day in Stornoway and
the first task for the team was to help load a large delivery of
food onto the vessel (thankfully including a large consignment of
teabags, which had run out!). This was achieved by means of a chain
gang - proper teamwork! The replacement camera arrived at about 1pm
and preliminary testing looked extremely promising which was a
relief. The new kit is due to be fully tested tomorrow morning to
ensure that it is all in fine working order. The team took
advantage of the brief time on dry land to explore Stornoway; a few
even braved a swim at a small rocky beach near the town! We were
lucky enough to do some seal watching from the dock just before
returning to the vessel for tea. A local Stornoway fishing vessel -
The Kaylana - began assisting the Franklin crew to
re-spool the winch and work on this task continued into the late
evening.

Day 6 - Monday 6th July 2009

Day breaks early this far north. For those on the night shift
there seems to be the briefest of nights before that clear, morning
light once more streams in through the portholes. The day began
well with another successful camera tow under our belts in a
somewhat more gravelly/coral rubble area. We then steamed to the
next station and deployed the gear for another transect. Over the
last few camera transects, we'd had problems with the video quality
from the drop frame; halfway down this tow, the video screen
suddenly went black, promptly followed by all the other camera
systems. It didn't look good! Once on board, a malfunction was
identified with the control module. A replacement was needed, so a
steam back to Stornoway became essential. Before departing the
area, a multibeam transect was conducted over the top of the
seamount, and this was continued until such time that departing the
area would mean arriving into Stornoway first thing in the morning.
We suspect this area to be vastly different from the flanks, more
of a sandy environment with perhaps some chance of
Lophelia coral. We have continued to have unbelievably
calm seas but as we turned for the Hebrides, the sea lifted and
showed us a little of what she can do.

Day 5 - Sunday 5th July 2009

We completed our first camera tow in the very early hours of the
morning, and started to winch the drop frame back to the boat. It
takes a long time to winch in 1500m cable and the drop frame didn't
get back to the boat until breakfast! However, it was quickly back
in the water, and for the second tow we were expecting a mixture of
soft and hard sediment. The tow began in a boulder strewn
environment before moving back into a silty environment.

A third tow was completed in the afternoon and we had a nerve
racking moment at the beginning, as on reaching the seabed we
noticed a discarded fishing net, which could have easily become
tangled up in the drop frame. Fishing nets are discarded at sea for
various reasons, and can remain extremely dangerous to marine life
as the nets continue to 'fish' - this phenomenon is termed
ghost
fishing. We observed this effect with a crab tangled up in the
discarded net. The third tow revealed yet another environment with
large boulders acting as hotspots for life in the middle of sandy
sediment. Every boulder was packed with colourful life, including
bright blue sponges, orange anemones and even the occasional
Lophelia coral colony.

A fourth tow was completed in the early evening along a very
steep ridge that extends out from the main seamount. We dropped
down immediately onto a deep coral reef with large
Lophelia colonies, gorgonian fans, encrusting sponges and
featherstars!

Day 4 - Saturday 4th July 2009

The sidescan towfish made it back on deck in the very early
hours of the morning, and it was quickly apparent as to why we had
lost communication. The cable connecting the towfish to the winch
on the boat is made up of extremely strong steel wires but the
forces twisting the cable had been so great that several of them
had snapped exposing the electronic wires inside! However, all is
not lost - repairs were carried out quickly and the sidescan
towfish is functional again. In the meantime we continued to
collect multibeam data for the south-east of Anton Dohrn and
processing began to get a better idea of what the seabed looks
like.

The weather was lovely in the afternoon with bright blue skies
and only a gently rolling swell. As such, JNCC staff took the
opportunity while off shift to complete some circuit training on
the front deck so we can remain fit and healthy. By late on
Saturday evening we were ready to do our first camera tow using the
drop frame. The drop frame holds both a video camera, so we can
record real-time, and a stills camera, so we can take
high-resolution photographs. During the deployment of the camera
frame, a downpour of rain had started, and everyone was startled
when a lightning bolt hit the sea 500m off our port side. You
could see a big spark where it hit the water, followed by a
tremendous crackle! On the first camera tow we lowered the drop
frame to nearly 1500m before reaching the seabed. From the acoustic
data we were anticipating a soft substrate at first followed by a
rock cliff with harder substrate at the bottom. We were rewarded
with a very silty environment at first, followed by a chalky cliff
and finally a gravel substrate at the bottom, which had seapens and
brittlestars. We also spotted a few deep sea fish such as
chimeras.

Day
3 - Friday 3rd July 2009

Today was the final leg of the transit to Anton Dohrn seamount,
and we arrived at the south-eastern flank in the late afternoon. En
route, we undertook some calibration testing of the dynamic
positioning (DP) system of the vessel. DP allows the vessel to move
along a predetermined course, generally regardless of direction of
currents, tide and wind. On this survey cameras will be dropped
into depths in excess of 1500m, directly below the ship. Due to the
long lengths of camera cable, underwater currents can force the
camera system a long way from this position. Acoustic 'pings' are
sent from the vessel to talk to the submerged camera, identifying
its location. The camera can then be manoeuvred along the chosen
transect by the vessel, allowing us to record images of the seabed
along our desired route.

Once we arrived at Anton in the late afternoon we began
collecting data for the same area with the deep-tow
sidescan and multibeam,
to allow comparison of the two different techniques. The sidescan
towfish (see photo below) is flown approximately 50m above the
seabed, almost 5 km behind the vessel. However, problems were
experienced when communications were lost with the towfish just
before it reached the seabed, and it was still being winched back
at midnight...

We also had an unusual visitor on board today - a crossbill.
Named MJ by Beth and Emma he was pretty exhausted and tried to
drink water from rain puddles on deck.

Day 2 - Thursday 2nd July 2009

We completed preliminary wet-testing of the camera drop frame
equipment early on Thursday morning, before beginning the long
transit to our first Area of Search, Anton Dohrn seamount. It was
time to catch a few hours sleep before breakfast. All scientific
personnel went on a safety briefing and familiarisation tour of the
vessel. By lunch, we were steaming through the Pentland Firth and
making good time. A fire drill was held mid-afternoon, when we had
to assemble on the aft deck at the muster station and try and get
into sea survival suits. As we were out on the aft deck, a bank of
enormous grey clouds appeared; as they passed overhead, the wind
started howling...and then the rain started! Luckily the squall
passed over quickly. We saw a pod of bottlenosed dolphins passing.
We also carried out some final modifications to the camera drop
frame equipment, to try and improve the quality of the images we
were getting, while the sea was shallow enough to get the
camera down to the seabed quickly to test it; it can take over
an hour to get the camera down to the seabed in the deep sea! The
first set of acoustic lines were plotted for Anton Dohrn. We should
arrive tomorrow afternoon to start surveying, fingers crossed the
weather stays good...

Day 1 - Wednesday 1st July 2009

We arrived on vessel first thing in the morning. It was a hive
of activity; engineers were setting up the drop-down camera frame
and other bits of equipment, while other supplies were being
loaded. We departed Regents Quay, Aberdeen at around dinner time
and after refuelling (which took a staggering 3 hours - that's a
lot of diesel!) headed out of the harbour before commencing the wet
testing of the equipment. The pilot guided the vessel out of the
harbour and we were on our way.